Hi Sonya, On the NZPCN website species pages you can scroll down to "Year naturalised". For Lotus pedunculatus (formerly L. major) the year naturalised is 1867 so it's not a recent introduction, but yes it would have been deliberately introduced primarily as a pasture plant. As you point out it has also become a popular species for hydroseeding, particularly on roadside cuttings and other steep man-made banks. There's nothing to stop contractors using lotus for hydroseeding, unless a Regional Council chose to restrict it's use for that purpose in their Regional Pest Management Plan. For a regional council to do this it would usually require someone who has an issue with it to put together a sound case to support them having such a rule. The other option is advocacy with the contractors themselves. There are other species suitable for hydro seeding. For example I remember years ago a contactor successfully used Ghania procera for hydroseeding banks along a new mine access road.